Synchronization of parallel gensets with source arbitration

• US 10,418,817 B2
• Filed: 07/29/2016
• Issued: 09/17/2019
• Est. Priority Date: 07/29/2016
• Status: Active Grant

• Current Assignee: Cummins Power Generation IP, Inc.
• Original Assignee: Cummins Power Generation IP, Inc.
• Inventors: Schultz, Mark H., Dahlen, Paul R.
• Primary Examiner(s): Sun, Pinping
• Application Number:
  US15/223,975
• Publication Number:
  US 20180034276A1
• Time in Patent Office: 1,145 Days
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/40 Synchronising a generator for connection to a network or to another generator

Abstract

A method of synchronization comprises receiving, at a first generator set, data indicating a characteristic for a component of a voltage for a source, and receiving, at a second generator set, the data indicating the characteristic for the component of the voltage for the source. The method also includes calculating, by each of the first and second generator sets, a speed offset parameter and a voltage offset parameter based on the received data. The first and second generator sets are configured to receive the same data indicating the component and independently calculate the same speed offset parameter and voltage offset parameter. The method further includes controlling operation of the first and second generator sets based on the calculated speed offset and voltage offset parameters.

Claims

1. A method of synchronization, comprising:

receiving, at a first generator set, data indicating a characteristic for a component of a voltage for a source;

receiving, at a second generator set, the data indicating the characteristic for the component of the voltage for the source;

calculating, by each of the first and second generator sets, a speed offset parameter and a voltage offset parameter based on the received data, the first and second generator sets configured to receive the same data indicating the component of the voltage for the source and independently calculate the speed offset parameter and the voltage offset parameter based on the same data indicating the component of the voltage for the source; and

controlling operation of the first and second generator sets based on the calculated speed offset and voltage offset parameters,

wherein the calculating the speed offset parameter comprises

generating the speed offset parameter based on a frequency and a phase of the voltage for the source and a frequency and a phase of an output voltage of the first generator set for the first generator set using a speed proportional integral loop of the first generator set,

wherein the calculating the voltage offset parameter comprises

generating the voltage offset parameter based on a magnitude of the voltage for the source and a magnitude of the output voltage of the first generator set using a magnitude proportional integral loop of the first generator set, and

wherein the controlling the operation of the first generator set comprises

controlling the magnitude of the output voltage of the first generator set based on the voltage offset parameter, the magnitude of the output voltage of the first generator set, and a reference magnitude using a voltage regulator proportional-integral-derivative controller of the first generator set.

2. The method of claim 1, wherein the characteristic for the component of the voltage for the source comprises at least one of the magnitude, the phase, or the frequency of the voltage for the source.

3. The method of claim 1, wherein the source comprises a plurality of phases, and wherein the characteristic for the component of the voltage for the source comprises at least one of a magnitude, a phase, or a frequency of each of the plurality of phases.

4. The method of claim 1, wherein the source comprises a plurality of phases, and wherein the characteristic for the component of the voltage for the source comprises at least one of a magnitude, a phase, or a frequency of a single phase of the plurality of phases.

5. The method of claim 1, wherein the source comprises a utility grid.

6. The method of claim 1, further comprising:

receiving the data from a node over a network;

comparing, by a controller located on the node, the output voltage of the first generator set with the received data; and

selectively closing or opening a first circuit breaker, by the controller, to connect or disconnect the first generator set to the source based on the comparison of the output voltage of the first generator set with the received data.

7. The method of claim 6, further comprising:

comparing, by the controller, an output voltage of the second generator set with the received data; and

selectively closing or opening a second circuit breaker, by the controller, to connect or disconnect the second generator set to the source based on the comparison of the output voltage of the second generator set with the received data.

8. The method of claim 1, wherein the controlling the operation of the first generator set further comprises:

controlling a speed of an engine of the first generator set based on the speed offset parameter, the frequency of the output voltage of the first generator set, and a reference frequency using a governor proportional-integral-derivative controller of the first generator set.

9. A method of synchronizing a group of paralleled generator sets, comprising:

receiving, at a first generator set of the group, a first synchronization request for synchronizing a first output of the first generator set to a first voltage component of a first source;

broadcasting, at the first generator set, a first identifier of the first source to at least a second generator set of the group;

receiving, at the first generator set, a second identifier of a second source from the second generator set, wherein the second generator set has received a second synchronization request for synchronizing a second output of the second generator set to a second voltage component of the second source;

selecting, at the first generator set, a source from the first source and the second source based on a characteristic of the first generator set and the second generator set; and

synchronizing the first output of the first generator set and the second output of the second generator set to the selected source.

10. The method of claim 9, wherein the first source comprises a first voltage bus on a power grid, and wherein the second source comprises a second voltage bus on the power grid.

11. The method of claim 9, wherein receiving the first synchronization request comprises receiving the first synchronization request from a first node over a network, and wherein receiving the second synchronization request comprises receiving the second synchronization request from a second node over the network.

12. The method of claim 9, wherein selecting the source from the first source and the second source comprises selecting a generator set from the first generator set and the second generator set that has a higher address, and selecting the source that is associated with the selected generator set.

13. The method of claim 9, further comprising:

receiving, at the first generator set, data indicating a magnitude, a frequency, and a phase of a voltage for the selected source;

receiving, at the second generator set, the data indicating the magnitude, the phase, and the frequency of the voltage for the selected source;

calculating, by each of the first and second generator sets, a speed offset parameter and a voltage offset parameter based on the received data, the first and second generator sets configured to receive the same magnitude, phase, and frequency of the voltage for the selected source and independently calculate the speed offset parameter and the voltage offset parameter based on the same received data; and

controlling operation of the first and second generator sets based on the calculated speed offset and voltage offset parameters.

14. The method of claim 13, wherein the calculating the speed offset parameter comprises:

generating the speed offset parameter based on the frequency and the phase of the voltage for the selected source and a frequency and a phase of an output voltage of the first generator set using a speed proportional integral loop of the first generator set.

15. The method of claim 9, wherein the first source and the second source comprise a plurality of phases, and wherein a first electrical power component and a second electrical power component comprise at least one of a magnitude, a phase, or a frequency of one or more of the plurality of phases.

16. A generator set comprising:

a communication interface configured to receive, over a network, a synchronization request for synchronizing an output voltage of the generator set to a voltage of a first source, and data indicating a magnitude, a frequency, and a phase of the voltage of the first source;

a magnitude synchronization circuit configured to calculate a voltage offset parameter based on the received data and to control operation of the generator set based on the calculated voltage offset parameter; and

a frequency/phase synchronization circuit configured to calculate a speed offset parameter based on the received data and to control the operation of the generator set based on the calculated speed offset parameter,

wherein the received data is transmitted to one or more other generator sets connected in parallel with the generator set and each of the one or more other generator sets configured to calculate the speed offset and the voltage offset using the same received data, and

wherein the magnitude synchronization circuit comprises;

a magnitude proportional integral loop configured to process the magnitude of the voltage of the first source and a magnitude of the output voltage of the generator set to generate the voltage offset parameter; and

an automatic voltage regulator configured to process the voltage offset parameter, the magnitude of the output voltage of the generator set, and a reference magnitude to control the magnitude of the output voltage.

17. The generator set of claim 16, wherein the communication interface comprises at least one of a modem, a network interface card, and a wireless transceiver.

18. The generator set of claim 16, wherein the frequency/phase synchronization circuit comprises:

a speed proportional integral loop configured to process the frequency and the phase of the voltage of the first source and a frequency and a phase of the output voltage of the generator set to generate the speed offset parameter; and

a governor proportional-integral-derivative controller configured to process the speed offset parameter, the frequency of the output voltage of the generator set, and a reference frequency to control a speed of an engine of the generator set.

19. The generator set of claim 18, wherein the generator set is in a group of paralleled generator sets, and wherein the communication interface is further structured to:

broadcast a first identifier of the first source to at least a second generator set of the group; and

receive a second identifier of a second source from the second generator set, wherein the second generator set has received a second synchronization request for synchronizing a second output voltage of the second generator set to a second voltage of the second source;

the generator set further comprising an arbitration circuit configured to;

select a source from the first source and the second source to which to synchronize the generator set.

20. The generator set of claim 19, wherein selecting the source from the first source and the second source comprises selecting a generator set from the first generator set and the second generator set that has a higher address, and selecting the source that is associated with the selected generator set.